<template>
    <el-breadcrumb class="app-breadcrumb breadcrumb-container" separator="/">
    <el-breadcrumb-item
      v-for="(item, index) in levelList"
      :key="item.path"
    >
      <!-- 面包屑导航最后一个是不可点击的 因为最后一个正是当前所显示的路由 -->
      <span
          v-if="index == levelList.length - 1"
          class="no-redirect"
        >
          {{ item.meta.title }}
      </span>
      <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
    </el-breadcrumb-item>
  </el-breadcrumb>
</template>

<script lang="ts">

import { defineComponent, ref, watch, onBeforeMount } from 'vue'
import { useRoute, useRouter, RouteLocationMatched, RouteLocationRaw } from 'vue-router'
import { compile } from 'path-to-regexp'
type PartialRouteLocationMatched = Partial<RouteLocationMatched>
export default defineComponent({
  name: 'Breadcrumb',
  setup(){
    const route =useRoute();
    const router =useRouter();
    const levelList = ref<Array<PartialRouteLocationMatched>>([])
    
    // 判断是不是Dashboard路由
    const isDashboard=(route:PartialRouteLocationMatched)=>{
      const name=route&& route.name;
      if(!name) return false
      return (name as string).trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
    }
    // 获取面包屑导航
    const getBreadcrumb=()=>{
      let matched =route.matched.filter(item=>item.meta&&item.meta.title) as PartialRouteLocationMatched[];
      const first=matched[0];
       // 我们要把dashboard作为首页 始终固定在面包屑导航第一个 Dashboard/System/Menu Management
      // 如果第一个匹配到的路由记录不是dashboard 我们自己就把它放在记录数组的第一项

      if(!isDashboard(first)){
         matched = ([{
          path: '/dashboard',
          meta: {
            title: 'Dashboard'
          }
        }] as PartialRouteLocationMatched[]).concat(matched)
      }
      // route.meta.breadcrumb自定义属性 如果为false 匹配到时 将不会再面包屑导航显示该路由
      // {
      //  path: 'menu',
      //  meta: {
      //    title: 'Menu Management',
      //    breadcrumb: false // 不显示在面包屑导航 默认true
      //  }
      // }
      levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)

    


    }
      onBeforeMount(()=>{
        getBreadcrumb()
      })
      // 监控path  改变面包屑
      watch(()=>route.path,()=>{
        getBreadcrumb()
      })

      // 主要是针对 动态路由 /user/:id 进行动态参数填充
    // path-to-regexp 文档说明 https://www.npmjs.com/package/path-to-regexp

    const pathCompile=(path:string)=>{
      const toPath=compile(path);
      const params=route.params;
      return toPath(params)
    }
    const handleLink = (route: RouteLocationMatched) => {
      const { path, redirect } = route
      // 如果是重定向路由 就走重定向路径
      if (redirect) {
        router.push(redirect as RouteLocationRaw)
        return
      }
      router.push(pathCompile(path))
    }
    return {
      levelList,
      handleLink
    }
  }
})
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  /* float: left; */
  line-height: 50px;
  font-size: 14px;
  margin-left: 8px;
}

.no-redirect {
  color: #97a8be;
  cursor: text;
}
</style>

<style lang="scss">

.breadcrumb-enter-active,
.breadcrumb-leave-active {
  transition: all .5s;
}

.breadcrumb-enter,
.breadcrumb-leave-active {
  opacity: 0;
  transform: translateX(20px);
}

.breadcrumb-leave-active {
  position: absolute;
}

.breadcrumb-move {
  transition: all .5s;
}
</style>